Steve Martan, 58, is a campus monitor at a school in the Tucson area. He allegedly left messages telling McSally to “be careful” when she returns to Tucson and that her days “were numbered,” as well as a specific threat to shoot her.

According to a criminal complaint filed Friday, Martan told FBI agents that he was angry about McSally voting to back President Donald Trump’s agenda.

Many Republicans are facing anger from constituents in the wake of the House vote for the GOP’s health care reform bill, which has resulted in many avoiding traditional town hall meetings in their district.

Most constituents have expressed their anger in protests, but some have gone beyond venting.

A Tennessee woman pled not guilty to reckless endangerment charges Monday after she allegedly chased Rep. David Kustoff’s car after a town hall, and screamed and hit its windows after they both stopped. Virginia Republican Rep. Tom Garrett has also received several death threats related to his vote on the health care bill, with one person reportedly saying he would kill Garrett if he lost his health care.

Threats of violence are particularly significant in McSally’s district, since it’s the one once represented by Gabrielle Giffords, who was seriously wounded in a shooting at a constituent event in 2011.

C.J. Karamargin, McSally's district director, told the Arizona Daily Star the threats were “especially sickening and shocking because of what this district has already endured with what happened to Congresswoman Giffords in 2011.” Karamargin was communications director for Giffords at the time of the mass shooting that seriously wounded her, killing six people and wounding 13. Since then, Giffords has committed herself to gun violence prevention.

“The threats of violence made against Congresswoman McSally are reprehensible and deeply disturbing,” Giffords said in a statement. “Civil discourse and civic engagement are hallmarks of our democracy, but threats and intimidation should never be tolerated.”